stddef.h(3HEAD) 						      Headers							   stddef.h(3HEAD)

NAME

       stddef.h, stddef - standard type definitions

SYNOPSIS

       #include <stddef.h>

DESCRIPTION

       The <stddef.h> header defines the following macros:

       NULL

	   Null pointer constant.

       offsetof(type, member-designator)

	   Integer constant expression of type size_t, the value of which is the offset in bytes to the structure member (member-designator), from
	   the beginning of its structure (type).

       The <stddef.h> header defines the following types:

       ptrdiff_t    Signed integer type of the result of subtracting two pointers.

       wchar_t	    Integer type whose range of values can represent distinct wide-character codes for all members of the  largest  character  set
		    specified  among the locales supported by the compilation environment: the null character has the code value 0 and each member
		    of the portable character set has a code value equal to its value when used as the lone character in an integer character con-
		    stant.

       size_t	    Unsigned integer type of the result of the sizeof operator.

       The  implementation supports one or more programming environments in which the widths of ptrdiff_t, size_t, and wchar_t are no greater than
       the width of type long. The names of these programming environments can be obtained using the confstr(3C) function or the getconf(1)  util-
       ity.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       getconf(1), confstr(3C), types.h(3HEAD), wchar.h(3HEAD), attributes(5), standards(5)

SunOS 5.11							    10 Sep 2004 						   stddef.h(3HEAD)